1. Field of the Invention
The field of the invention is data processing, or, more specifically, methods, apparatus, and products for identifying an optimized test bit pattern for analyzing electrical communications channel topologies.
2. Description Of Related Art
The development of the EDVAC computer system of 1948 is often cited as the beginning of the computer era. Since that time, computer systems have evolved into extremely complicated devices. Today's computers are much more sophisticated than early systems such as the EDVAC. Computer systems typically include a combination of hardware and software components, application programs, operating systems, processors, buses, memory, input/output devices, and so on. As advances in semiconductor processing and computer architecture push the performance of the computer higher and higher, more sophisticated computer software has evolved to take advantage of the higher performance of the hardware, resulting in computer systems today that are much more powerful than just a few years ago.
Today's computer systems often contain many high speed communications channels. The effect of various design parameters of communications channels on the integrity of high frequency signals carried by the communication channels is constantly increasing. Modeling such effects is also increasingly more difficult. Often it is cost-prohibitive or time-prohibitive to physically implement such design parameters for evaluating performance of the communications channel. Analyzing the effects of various design parameters of a communications channel in a pre-layout design space is an economical alternative to physically implementing the various design parameters. One common way to analyze the quality of a communications channel is to plot an eye diagram of a signal at the receiver, where the signal is transmitted through the communications channel. Finding the best and worst cases of all the various design parameters for a communications channel is important to perform effective pre-layout analysis. To accurately estimate a realistic eye diagram for a particular set of the various design parameters, it is common practice to apply a long random bit stream to the communications channel. While long bit streams contain enough power to excite the communications channel uniformly across the relevant bandwidth, simulation and analysis of such a long random bit stream is time consuming. Reducing the length of the bit stream may reduce analysis time but may also provide inaccurate results with respect to different sets of the various design parameters of the communications channel.